1. Field of the Invention
The present invention relates to devices and methods for stimulation of hypothalamic activity in a human subject by imparting vibrations to the posterior part of the nasal cavity of the human subject.
2. Description of Background Art
The hypothalamus is a portion of the brain which lies beneath the thalamus and which contains a number of small nuclei with a variety of functions. One of the most important functions of the hypothalamus is to provide a link between the nervous system and the endocrine system via the pituitary gland (hypophysis). The hypothalamus has an influence on certain metabolic processes by secreting certain neurohormones, often called hypothalamic-releasing hormones, which in turn stimulate or inhibit the secretion of pituitary hormones. It also regulates other glands such as the ovaries, parathyroids and thyroid and has a degree of control over sleeping patterns, eating, drinking and speech. Moreover, the hypothalamus is involved in the regulation of body temperature, water balance, blood sugar and fat metabolism. Several illnesses are associated with hypothalamic dysfunction, such as migraine, Ménière's disease, hypertension, cluster headache, arrhythmia, ALS, irritable bowel syndrome, sleep disorders, diabetes, obesity, multiple sclerosis, tinnitus, Alzheimer's disease, mood and anxiety disorders and epilepsy. In many cases the connection between the hypothalamus and the illness in question is not fully understood. In addition, many of the illnesses listed above lack satisfactory therapies.
Ménière's disease (MD), for example, is a relatively rare disease affecting the inner ear. The disease is characterized by episodic vertigo, fluctuating hearing loss, aural pressure and tinnitus. MD is a progressive disorder that most often results in severe hearing deterioration. No otoprotective interventions currently exist and chemical or surgically destructive procedures are used for treatment beyond the acute phase.
Cluster headache (CH), also called Horton's headache, is another example of an illness with a suggested connection to hypothalamus and which lacks a successful treatment method. CH is the most severe disorder among primary headache disorders. It is characterized by recurrent short-lasting attacks of torturous unilateral periorbital pain, mostly accompanied by ipsilateral autonomic signs such as nasal congestion, ptosis, lacrimation and redness of the eye. Ipsilateral autonomic signs are signs of autonomic dysfunction; ipsilateral lacrimation, redness of the eye and nasal congestion are signs of parasympathetic hyperactivity, and the combination of ptosis and miosis is a sign of sympathetic hypoactivity. New surgical therapies have been tested. However, these treatments are invasive and can cause severe complications. The pathophysiology of CH is currently unknown, but involvement of the hypothalamus and the parasympathetic nervous system has been proposed (Leoux E et al, Orphanet J of Rare Diseases; 2008, 3:20)
Yet another example of an illness where involvement of hypothalamus has been suggested is migraine (Alstadhaug K B, Cephalalgia; 2009, 29: 809). Migraine is a complex multi-factorial disorder of the brain that is characterized by episodes of headache and super-sensitivity to sensory stimuli. Migraine is a type of primary headache disorder, and can be broadly categorized as migraine without aura and migraine with aura. The clinical features in migraine are thought to result from dysfunction of the parasympathetic nervous system.
There are several known devices for conducting treatments with systemic effects in patients. Devices for use in for example the nasal cavity however often aim at achieving a local effect, such as decongesting the nasal mucosa, and may often be used in combination with a chemical substance. One example of a device for achieving a local effect on the nasal mucosa is disclosed in WO 2008/138997.
Devices are also known that by mechanical vibration in a body cavity affect body functions. In US 2008/0281238, a system for increasing activity in the fundamental brain is disclosed. The disclosed system comprises a first and a second vibration applying device, wherein the first vibration applying device applies vibrations having frequency components within an audible range to the auditory sense system of a living body. The second vibration applying device applies vibrations having super-high frequency components exceeding the audible range to another region than the auditory sense system, such as the nasal cavity.
In RU 2199303 there is disclosed a method of treating the neuroautonomic form of vasomotor rhinitis. More specifically, the method involves vibratory massage of the anterior third of the inferior and middle conchae at a frequency of 50 Hz for 1.5-2 minutes in combination with vibratory massage of certain biological active points (BAP:s) located in the hand, chin and near the nose. The instrument used for delivering the vibratory massage is described as a vibromassage instrument having a ball and a tip.